Summary: Astronomy & Astrophysics manuscript no. 4259 c ESO 2005
November 16, 2005
Multi-wavelength study of a high velocity event near a sunspot
Chia-Hsien Lin1, D. Banerjee2, E. O'Shea1, and J.G. Doyle1
Armagh Observatory, College Hill, Armagh BT61 9DG, N. Ireland
Indian Institute of Astrophysics, Koramangala, Bangalore 560034, India
Context. Jets with velocities higher than 200 km s-1
are often observed in the X-ray spectral range in the solar atmosphere, however, very few
such objects are observed in the EUV range.
Aims. We report on an eruptive event observed in the south-west side of a sunspot, within active region, AR0554, in a range of spectral lines
formed in the transition region and corona.
Methods. The main data were time-series observations obtained with the Coronal Diagnostic Spectrometer (CDS), in addition to images from
the Michelson Doppler Imager (MDI) and Extreme ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory.
Additional high resolution images from the Transition Region and Coronal Explorer (TRACE) were also used.
Results. The event brightened a loop connecting the sunspot and a bright-point structure, triggering both a high-speed flow in the loop and
a transient, low-speed ambient flow into the sunspot. The energy released is quickly conducted to the chromosphere, as deduced from the
TRACE 1600 Å images and the light curve of He I 522 Å as seen by CDS. The results from our multi-wavelength study further indicates that